Home > Publications database > Comparison of different methods for activation analysis of geological and pedological samples : reactor and epithermal neutron activation, relative and monostandard method |
Report | FZJ-2016-07091 |
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1982
Kernforschungsanlage Jülich GmbH Zentralbibliothek, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/13122
Report No.: Juel-Spez-0075
Abstract: Using purely instrumental methods, a comparative study is presented on neutron activation analysis of rock and soil samples by whole reactor neutron spectrum and epithermal neutrons with both relative and monostandard procedures. The latter procedure used with epithermal neutron activation analysis of soil samples necessitated the use of the "effective resonance integrals" which were determined experimentally. The incorporation of the $\beta$ factor, representing deviation of reactor epithermal neutron flux from 1/Elaw, is developed in the present work. The main criteria for the choice of one or more of the procedures studied for a given purpose are also indicated. Analysis of 15 trace elements, Ca and Fe in the standard Japanese granite JG-1 using monostandard epithermal neutron activation gave results in good agreement with the average literature values. Under normal laboratory routine conditions, realistic detection limits, precisions and accuracies are given. More in detail are discussed the precision and accuracy obtained for the rock and soil samples with respect to different neutron activation analysis methods as well as different samples. Assuming a quasi-normal distribution of the precision for all elements and methods investigated and eliminating 7 outliers out from the 248 data, an arithmetic mean of ± 15,3 rel-% and a median of ± 14 rel-% has been obtained. Therefore, the overall precision with all elements, samples and NAA methods is about ± 15 rel-%. The accuracy obtained for the example of granite JG-1 was about -10 to + 20 rel-%, most values between -1 and +5 rel-%. The overall accuracy with all elements of JG-1 is as good as -1,7 %, neglecting one outlier at -47,5 %.
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